Detection of GTP-tubulin conformation in vivo reveals a role for GTP remnants in microtubule rescues.
Microtubules display dynamic instability, with alternating phases of growth and shrinkage separated by catastrophe and rescue events. The guanosine triphosphate (GTP) cap at the growing end of microtubules, whose presence is essential to prevent microtubule catastrophes in vitro, has been difficult to observe in vivo. We selected a recombinant antibody that specifically recognizes GTP-bound tubulin in microtubules and found that GTP-tubulin was indeed present at the plus end of growing microtubules. Unexpectedly, GTP-tubulin remnants were also present in older parts of microtubules, which suggests that GTP hydrolysis is sometimes incomplete during polymerization. Observations in living cells suggested that these GTP remnants may be responsible for the rescue events in which microtubules recover from catastrophe.
Dimitrov
Ariane
A
CNRS UMR144, Institut Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, France.
Quesnoit
Mélanie
M
Moutel
Sandrine
S
Cantaloube
Isabelle
I
Poüs
Christian
C
Perez
Franck
F
D000818:Animals; D000906:Antibodies / Q000276:immunology; D002460:Cell Line; D003198:Computer Simulation; D019281:Dimerization; D005455:Fluorescent Antibody Technique; D006160:Guanosine Triphosphate / Q000032:analysis* / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008870:Microtubules / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D008954:Models, Biological; D009010:Monte Carlo Method; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014404:Tubulin / Q000032:analysis / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism
D000906:Antibodies; D011993:Recombinant Fusion Proteins; D014404:Tubulin; D006160:Guanosine Triphosphate